Recreate database schema extras on migration

8 files changed, 57 insertions, 24 deletions

diff --git a/INSTALL b/INSTALL
index 36b3465..51c9c06 100644
--- a/INSTALL
+++ b/INSTALL
@@ -208,7 +208,7 @@ $ install/bin/brep-migrate build
 
 To verify:
 
-$ psql -d brep_package -c 'SELECT name, summary FROM repository'
+$ psql -d brep_package -c 'SELECT canonical_name, summary FROM repository'
 $ psql -d brep_build -c 'SELECT package_name FROM build' # Empty row set.
 $ psql -d brep_build -c 'SELECT DISTINCT name FROM build_package'
 
diff --git a/INSTALL-DEV b/INSTALL-DEV
index b051cb2..e6c46cd 100644
--- a/INSTALL-DEV
+++ b/INSTALL-DEV
@@ -127,7 +127,7 @@ $ migrate/brep-migrate build
 
 To verify:
 
-$ psql -d brep_package -c 'SELECT name, summary FROM repository'
+$ psql -d brep_package -c 'SELECT canonical_name, summary FROM repository'
 $ psql -d brep_build -c 'SELECT package_name FROM build' # Empty row set.
 $ psql -d brep_build -c 'SELECT DISTINCT name FROM build_package'
 
diff --git a/libbrep/.gitignore b/libbrep/.gitignore
index 1fbfc28..1cf5d3e 100644
--- a/libbrep/.gitignore
+++ b/libbrep/.gitignore
@@ -2,9 +2,13 @@ common-odb.?xx
 
 package-odb.?xx
 package.sql
+package-???-pre.sql
+package-???-post.sql
 package-extra.hxx
 
 build-odb.?xx
 build-package-odb.?xx
 build.sql
+build-???-pre.sql
+build-???-post.sql
 build-extra.hxx
diff --git a/libbrep/build-extra.sql b/libbrep/build-extra.sql
index cc43239..35ba361 100644
--- a/libbrep/build-extra.sql
+++ b/libbrep/build-extra.sql
@@ -2,6 +2,9 @@
 -- parser complexity, there is a number of restrictions, see package-extra.sql
 -- file for details.
 --
+-- Increment the database 'build' schema version when update this file, see
+-- package-extra.sql file for details.
+--
 
 DROP FOREIGN TABLE IF EXISTS build_package_constraints;
 
diff --git a/libbrep/package-extra.sql b/libbrep/package-extra.sql
index 93c61d8..86f055b 100644
--- a/libbrep/package-extra.sql
+++ b/libbrep/package-extra.sql
@@ -8,6 +8,13 @@
 -- * strings other then function bodies must be quoted with ' or "
 -- * statements must end with ";\n"
 --
+-- Increment the database 'package' schema version when update this file. Note
+-- that the brep-migrate utility executes the drop SQL statements prior to the
+-- schema migration and the create statements afterwards. That, in particular,
+-- means that the extras may depend on the tables but not the other way
+-- around. Make sure that the drop statements properly handle entities created
+-- for all schema versions starting from LIBBREP_PACKAGE_SCHEMA_VERSION_BASE.
+--
 
 -- There is no need to drop to_tsvector() explicitly, as we can rely on "DROP
 -- TYPE IF EXISTS weighted_text CASCADE" statement below, which will drop all
diff --git a/libbrep/package.hxx b/libbrep/package.hxx
index fbe6f60..af4581c 100644
--- a/libbrep/package.hxx
+++ b/libbrep/package.hxx
@@ -21,7 +21,7 @@
 //
 #define LIBBREP_PACKAGE_SCHEMA_VERSION_BASE 7
 
-#pragma db model version(LIBBREP_PACKAGE_SCHEMA_VERSION_BASE, 7, closed)
+#pragma db model version(LIBBREP_PACKAGE_SCHEMA_VERSION_BASE, 8, open)
 
 namespace brep
 {
diff --git a/libbrep/package.xml b/libbrep/package.xml
index 7b74349..07c1be7 100644
--- a/libbrep/package.xml
+++ b/libbrep/package.xml
@@ -1,4 +1,6 @@
 <changelog xmlns="http://www.codesynthesis.com/xmlns/odb/changelog" database="pgsql" schema-name="package" version="1">
+  <changeset version="8"/>
+
   <model version="7">
     <table name="repository" kind="object">
       <column name="tenant" type="TEXT" null="false"/>
diff --git a/migrate/migrate.cxx b/migrate/migrate.cxx
index af0890f..d84e282 100644
--- a/migrate/migrate.cxx
+++ b/migrate/migrate.cxx
@@ -40,10 +40,10 @@ public:
   schema (const char* extra, string name);
 
   void
-  create (database&) const;
+  create (database&, bool extra_only = false) const;
 
   void
-  drop (database&) const;
+  drop (database&, bool extra_only = false) const;
 
 private:
   string name_;
@@ -177,7 +177,7 @@ schema (const char* s, string name)
 }
 
 void schema::
-drop (database& db) const
+drop (database& db, bool extra_only) const
 {
   for (const auto& s: drop_statements_)
     // If the statement execution fails, the corresponding source file line
@@ -187,15 +187,17 @@ drop (database& db) const
     //
     db.execute (s);
 
-  schema_catalog::drop_schema (db, name_);
+  if (!extra_only)
+    schema_catalog::drop_schema (db, name_);
 }
 
 void schema::
-create (database& db) const
+create (database& db, bool extra_only) const
 {
-  drop (db);
+  drop (db, extra_only);
 
-  schema_catalog::create_schema (db, name_);
+  if (!extra_only)
+    schema_catalog::create_schema (db, name_);
 
   for (const auto& s: create_statements_)
     db.execute (s);
@@ -289,6 +291,9 @@ try
   //
   schema_version schema_version (db.schema_version (db_schema));
 
+  odb::schema_version schema_current_version (
+    schema_catalog::current_version (db, db_schema));
+
   // It is impossible to operate with the database which is out of the
   // [base_version, current_version] range due to the lack of the knowlege
   // required not just for migration, but for the database wiping as well.
@@ -301,7 +306,7 @@ try
       throw failed ();
     }
 
-    if (schema_version > schema_catalog::current_version (db, db_schema))
+    if (schema_version > schema_current_version)
     {
       cerr << "error: database schema is too new" << endl;
       throw failed ();
@@ -317,8 +322,9 @@ try
   // Let the user decide if they want to migrate or just drop the entire
   // database (followed with the database creation for the --recreate option).
   //
-  if ((create || drop) && schema_version != 0 &&
-      schema_version != schema_catalog::current_version (db, db_schema))
+  if ((create || drop)    &&
+      schema_version != 0 &&
+      schema_version != schema_current_version)
   {
     cerr << "error: database schema requires migration" << endl
          << "  info: either migrate the database first or drop the entire "
@@ -326,34 +332,45 @@ try
     throw failed ();
   }
 
-  transaction t (db.begin ());
-
-  if (create || drop)
-  {
-    static const char package_extras[] = {
+  static const char package_extras[] = {
 #include <libbrep/package-extra.hxx>
-      , '\0'};
+    , '\0'};
 
-    static const char build_extras[] = {
+  static const char build_extras[] = {
 #include <libbrep/build-extra.hxx>
-      , '\0'};
+    , '\0'};
+
+  schema s (db_schema == "package" ? package_extras : build_extras,
+            db_schema);
 
-    schema s (db_schema == "package" ? package_extras : build_extras,
-              db_schema);
+  transaction t (db.begin ());
 
+  if (create || drop)
+  {
     if (create)
       s.create (db);
     else if (drop)
       s.drop (db);
   }
-  else
+  else if (schema_version != schema_current_version)
   {
+    // Drop the extras, migrate the database tables and data, and create the
+    // extras afterwards.
+    //
+    // Note that here we assume that the latest extras drop SQL statements can
+    // handle entities created by the create statements of the earlier schemas
+    // (see libbrep/package-extra.sql for details).
+    //
+    s.drop (db, true /* extra_only */);
+
     // Register the data migration functions.
     //
     // static const data_migration_entry<2, LIBBREP_XXX_SCHEMA_VERSION_BASE>
     // migrate_v2_entry (&migrate_v2);
     //
     schema_catalog::migrate (db, 0, db_schema);
+
+    s.create (db, true /* extra_only */);
   }
 
   t.commit ();